Brightness-dependent adjustment of a spectacle lens

ABSTRACT

Adjustment of an eyeglass lens or a pair of eyeglasses by means of an individual brightness-dependent centering of an eyeglass lens. In particular, a method for adjusting an individual eyeglass lens for at least one eye of an eyeglass wearer. The method includes defining an individual usage situation which includes at least one target brightness value for the light to be captured by the at least one eye; determining a position of the pupil in at least one direction of view of the at least one eye which occurs or is expected at the at least one target brightness value; determining a reference point of the eyeglass lens, in which the eyeglass lens effects a required correction of individual refraction data for the at least one direction of view; on the basis of the determined individual value of the pupil position, providing and arranging the eyeglass lens in such a manner that the at least one reference point of the eyeglass lens is arranged in front of the at least one eye of the eyeglass wearer.

The present invention relates to the optimization and production ofspectacle lenses for a spectacle wearer taking into considerationlighting conditions of an individual situation of wear, for which therespective spectacle lens is to be optimized.

For the production or optimization of spectacle lenses, in particular ofindividual spectacle lenses, each spectacle lens is manufactured suchthat the best possible correction of a refractive error of therespective eye of the spectacle wearer is obtained for each desireddirection of sight or each desired object point. In general, a spectaclelens is said to be fully correcting for a given direction of sight ifthe values sphere, cylinder, and axis of the wavefront, upon passing thevertex sphere, match with the values for sphere, cylinder, and axis ofthe prescription for the eye having the visual defect. In the refractiondetermination for an eye of a spectacle wearer, dioptric values(particularly sphere, cylinder, cylinder axis) for a far (usuallyinfinite) distance and optionally (for multifocal or progressive lenses)an addition for a near distance (e.g. according to DIN 58208) aredetermined. In this way, the prescription (in particular sphere,cylinder, cylinder axis, and optionally addition) that is sent to aspectacles manufacturer is stipulated. In modern spectacle lenses,object distances deviating from the standard, which are used in therefraction determination, can be indicated additionally.

However, a full correction for all directions of sight at the same timeis normally not possible. Therefore, the spectacle lenses aremanufactured such that they achieve a good correction of visual defectsof the eye and only small aberrations in the main zones of use,especially in the central visual zones, while larger aberrations arepermitted in peripheral zones.

In order to be able to manufacture a spectacle lens in this way, thespectacle lens surfaces or at least one of the spectacle lens surfacesis first of all calculated such that the desired distribution of theunavoidable aberrations is effected thereby. This calculation andoptimization is usually performed by means of an iterative variationmethod by minimization of a target function. As a target function,particularly a function F having the following functional relation withthe spherical power S, the magnitude of the cylindrical power Z, and theaxis of the cylinder a (also referred to as “SZA” combination) is takeninto account and minimized:

$F = {\sum\limits_{i = 1}^{m}\; {\left\lbrack {{g_{i,{S\; \Delta}}\left( {S_{\Delta,i} - S_{\Delta,i,{target}}} \right)}^{2} + {g_{i,{Z\; \Delta}}\left( {Z_{\Delta,i} - Z_{\Delta,i,{target}}} \right)}^{2} + \ldots} \right\rbrack.}}$

In the target function F, at the evaluation points i of the spectaclelens, at least the actual refractive deficits of the spherical powerS_(Δ,i) and the cylindrical power Z_(Δ,i) as well as targetspecifications for the refractive deficits of the spherical powerS_(Δ,i,target) and the cylindrical power Z_(Δ,i,target) are taken intoconsideration.

It was found in DE 103 13 275 that it is advantageous to not indicatethe target specifications as absolute values of the properties to beoptimized, but as their deviation from the prescription, i.e. as therequired misadjustment. This has the advantage that the targetspecifications are independent of the prescription (Sph_(V), Zyl_(V),Axis_(V), Pr_(V), B_(V)) and that the target specifications do not haveto be changed for every individual prescription. Thus, as “actual”values of the properties to be optimized, not absolute values of theseoptical properties are taken into account in the target function, butthe deviations from the prescription. This has the advantage that thetarget values can be specified independent of the prescription and donot have to be changed for every individual prescription.

The respective refractive deficits at the respective evaluation pointsare preferably taken into consideration with weighting factors g_(i,SΔ)and g_(i,ZΔ). Here, the target specifications for the refractive deficitof the spherical power S_(Δ,i,target) and/or the cylindrical powerZ_(Δ,i,target), particularly together with the weighting factorsg_(i,SΔ) and g_(i,ZΔ), form the so-called “design” or spectacle lensdesign. In addition, particularly further residues, especially furtherparameters to be optimized, such as coma and/or spherical aberrationand/or prism and/or magnification and/or anamorphic distortion, etc.,can be taken into consideration, which is particularly implied by theexpression “+ . . . ”. Thus, the design of a spectacle lens inparticular specifies the way the aberrations are distributed on thespectacle lens. Preferably, it is specified for a plurality ofevaluation points on the spectacle lens how large the aberration to beobtained and optionally its weighting in the target function are to be.

Preferably, the design of a spectacle lens also comprises a setting ofthe position of one or more marked points, in particular referencepoints, such as the position of a distance reference point and/or of anear reference point and/or of a prism reference point and/or of acentration point and/or of a position or a course of a principal line ofsight. While in the beginning of progressive lenses spectacle lenseswere specified by the spectacle lens manufacturer in a graded fashionaccording to different categories, the adaptation of spectacle lensesfor individual spectacle wearers has been individualized increasinglythroughout the years. Specifically, the spectacle lens designs havetaken into account individual conditions, such as dimensions andposition of the individual spectacles frame (e.g. forward inclination,face form angle), habitual parameters (e.g. head posture, headmovement), an individual situation of wear (individual object distancemodel), or individual anatomical conditions (e.g. corneal vertexdistance).

In addition to the design of the spectacle lens, the correct centrationis of importance as well. For example, for the adaptation ofspectacles—in addition to other parameters—mainly the pupillary distancefor far vision (far PD) is measured. In the case of progressive lenses,usually—also for otherwise highly individualized lenses—the far PD ismeasured and for the determination of the near PD or the course of themain line of sight a simplified model (rotation of the eye around apoint) and standard parameters (usually the eye radius from theGullstrand model, cf. DIN 5340) are used. The far PD is measuredapproximately with most conventional video centration systems by settinga visual task for a specified distance to the device, which isconsidered to be sufficiently large.

To further improve an individual adaptation of a spectacle lens orspectacles, even more detailed models for describing the eye's anatomyand the muscular system moving the eye have been considered as well. Forexample, different axes with different radii can be set for horizontaland vertical rotations. Moreover, it is possible to distinguish betweenthe mechanical and the optical ocular centers of rotation. Despite theefforts made to determine the individual eye movement as precisely aspossible, the quality of the individual adaptation of a spectacle lensor spectacles is limited.

For adapting spectacles, in addition to other parameters, in particularthe position of the pupil (pupillary distances and fitting heights) forfar vision under generally undefined lighting conditions has so far beenmeasured manually or by means of video centration systems. The actualsizes or positions of the pupils for the lighting conditions prevailingin the later use of the spectacles are not taken into considerationhere.

It is the object of the present invention to achieve an improvement ofthe individual adaptation of spectacle lenses. This object is solved bymethods having the features indicated in claim 1 or 2 and by a measuringapparatus having the features indicated in claim 12. Preferredembodiments are subject of the dependent claims.

According to one aspect, the invention provides a method for adapting,in particular optimizing and producing, an individual spectacle lens forat least one eye of a spectacle wearer, comprising in particularcollecting individual data for the least one eye of the spectaclewearer. Here, collecting individual data comprises specifying anindividual situation of wear, which comprises at least one brightnesstarget value for the light to be captured by the at least one eye in theintended situation of wear, in which the spectacle lens is to be used. Atarget value of the (medium) luminance is preferably specified as thebrightness target value. Preferably, the individual situation of wearalso specifies an object distance model at least partly, i.e. itspecifies the distance from objects expected in the individual situationof wear of a spectacle lens to be adapted for at least one or severaldirections of sight. For a progressive lens, for example, at least theexpected object distance for a direction of sight corresponding to adistance reference point of the spectacle lens and for a direction ofsight corresponding to a near reference point of the spectacle lens isspecified.

Further, the method (in particular collecting individual data) comprisesdetermining an individual position, occurring or expected for the atleast one brightness target value, of the pupil of the at least one eyefor at least one direction of sight of the at least one eye, i.e. in atleast one eye position. That is, what is determined is the individualposition of the pupil resulting for the at least one eye of thespectacle wearer for the target value, specified in the individualsituation of wear, of the (medium) luminance detected by the eye. Inparticular two alternative approaches are preferred here.

In one of these preferred approaches, the individual position of thepupil is detected (directly or indirectly), while the at least one eyeis subjected to the specified brightness target value. That is, thebrightness condition expected in the later actual situation of wear isset during the detection of the pupil position in the at least onedirection of sight.

In another preferred approach, a formal relation between brightness andthe position of the pupil of the at least one eye is specified. Further,the brightness acting on the eye during the detection of the position ofthe pupil is detected. This is followed by a corresponding correction ofthe position of the pupil for transformation to the brightness targetvalue by means of the specified relation between brightness and theposition.

Specifying the at least one brightness target value is preferablyperformed by a user input, either directly as a numerical value or byselection from among predetermined numerical values or from apredetermined value range, or by selection from predeterminedapplication fields for which typical brightness values are deposited(e.g. differentiation between day and night spectacles for vehicledrivers; outdoor sports, computer work, etc.). So far, such situationsof wear have been occasionally distinguished in the typical objectdistances, but the brightness and its individual influence on theposition of the pupil to be expected in the individual case have notbeen taken into consideration. Thus, in the measurement of the eyes, inparticular for a centration, attention has so far not been paid to theactual brightness prevailing during the measurement.

In the present invention, however, it has been found that by consideringthe actual brightness in the individual situation of wear and itsindividual influence on the position of the pupil, in particular in anasymmetrical adaptation of the pupil for different brightnesses, animprovement of the individual adaptation of spectacle lenses is easilyachieved already in the centration of a spectacle lens alone, butpreferably also in the optimization and production of a spectacle lens.

The method further comprises determining a reference point of thespectacle lens, in which the spectacle lens causes a correction ofindividual refraction data required for the at least one direction ofsight. The requirement of correction is preferably specified by a targetfunction, in which individually determined refraction data, inparticular for different directions of sight (e.g. as refractive powercourse), together with tolerances or specifications for deviations fromthe full correction (the so-called design) are taken into account.Depending on the intended application, the refraction data is collectedpreferably even for a plurality of directions of sight. Thus, for amultifocal lens or a progressive lens, preferably at least one distancerefraction and one near refraction of the at least one eye are detected,from which in particular also the required addition results for aprogressive lens.

For every direction of sight, the required optical power of thespectacle lens to be optimized and produced depends on the distance ofthe objects in the intended situation of wear. The distance is describedby the predetermined object distance model preferably for everysituation of wear. A distance reference point and/or a near referencepoint and/or a centration point of the spectacle lens can e.g. beselected as at least one reference point. The individual refraction tobe at least partly corrected in the at least one reference point caneither be measured directly for the spectacle wearer (e.g. for thedistance or the near reference point) or be derived from measured valuesfor other directions of sight e.g. from a desired course of a powerincrease between distance and near zones (e.g. for a reference pointdeviating from the distance or the near reference point).

Moreover, the method comprises providing and arranging the spectaclelens (in particular fitting the spectacle lens in the frame) such thatthe at least one reference point of the spectacle lens (e.g. thecentration point) is arranged depending on the determined individualvalue of the position of the pupil, in front of the at least one eye ofthe spectacle wearer. In particular, in other words, the spectacle lensis provided and arranged (or designed for arrangement) such that in theindividual situation of wear, when looking in the at least one directionof sight for which the individual value of the position of the pupil(i.e. the individual position of the pupil) was determined, thespectacle wearer looks through the determined reference point of thespectacle lens. Thus, preferably a centration point of the spectaclelens used as a reference point is arranged horizontally in front of theposition of the pupil predetermined or to be expected for the specifiedbrightness target value particularly for a view in the at least onedirection of sight. In particular for the fitting of the lens in thespectacles frame, a centration of the spectacle lens depending on thebrightness occurring in the individual situation of wear is performed.

While so far for the centration of the spectacle lens attention has notbeen paid to neither the brightness at the moment the centration data(e.g. pupillary distance or fitting height) is measured nor to thebrightness for the desired situation of application, an individualbrightness-dependent centration is performed according to the inventionby determining and considering the individual influence of thebrightness on the pupil position.

In the following, centration does not only mean the positioning of thespectacle lenses in the frame, but preferably also the location of thedesign points with respect to each other and preferably even the courseof the principal line of sight.

In a further aspect of the invention, even the individualbrightness-dependent position of the pupil is taken into account in theoptimization of a spectacle lens. In this aspect, the invention thusprovides a method for optimizing and producing an individual spectaclelens for at least one eye of a spectacle wearer, comprising specifyingan individual situation of wear, which specifies a brightness targetvalue for the light to be captured by the at least one eye for at leasttwo different reference points of the spectacle lens. Data of weardescribing the individual situation of wear comprises a value for thebrightnesses to be expected. In this way, a brightness-dependentconsideration of the position of the pupil for various directions ofsight is performed in the optimization and production of a spectaclelens. Here, the brightness expected (specified) in the individualsituation of wear may well be the same for all directions of sight (inparticular for the two reference points). It is preferably sufficient tospecify one single brightness target value that can then be applied toall reference points.

Further, the method comprises determining refraction data of the atleast one eye for the at least two different reference points and thusin particular for a plurality of object distances, in particular for atleast two viewing zones or directions of sight, which in particularcorrespond to far vision and near vision.

The reference points in particular of a progressive lens couldpreferably be a distance reference point and a near reference point.Here, in particular different brightness target values in the individualsituation of wear are specified for the distance and near referencepoints. The different brightness in the individual situation of wearoccurring in the distance and near reference points can individuallylead to different positions and/or sizes of the pupil. To take this intoaccount in the optimization and production of the spectacle lens, inparticular these reference points are adapted according to theindividual, brightness-dependent pupil position, i.e. in particularshifted based on a target design (starting design) created withoutconsidering a dependence of the pupil position on the brightness.

A differentiation between distance and near vision is particularlydesired for progressive spectacle lenses. In this case, preferablydifferent refraction data results for the at least two reference points.Considering the individual influence of the brightness on the positionof the pupil in the optimization process is also advantageous forreference points in which same refraction data of the eye are to becorrected. Thus, the approach according to the invention provides animprovement of the individual adaptation in particular also forindividually calculated (optimized) single-vision lenses.

To this end, the method comprises determining an individual influence ofthe brightness of the light captured by the at least one eye on theposition of the pupil of the at least one eye and optimizing andproducing the spectacle lens, which causes a correction, destined forthe reference points, of the refraction data for the positions of thepupil of the at least one eye, which result from the determinedinfluence of the brightness on the position of the pupil for thebrightness target values specified for the reference points.

In the present invention, it has been found that an improvement of theindividual adaptation of spectacles or a spectacle lens can be obtainedby performing a brightness-dependent centration and/or optimization in away in which in particular individual, non-symmetrical changes of apupil in an adaptation to the brightness (adaptation) are at leastpartly considered.

Optimizing the spectacle lens preferably comprises minimizing a targetfunction, in particular according to the above-mentioned target functionF. Particularly preferably, the method comprises determining anindividual position and/or size of the pupil respectively occurring orexpected for the specified brightness target values, wherein optimizingthe spectacle lens comprises minimizing a target function which, for theat least two reference points, evaluates a correction of the refractiondata respectively determined for the respective reference point, saidcorrection being caused by the spectacle lens in a surrounding of therespective reference point, wherein in particular the size of thesurrounding of the respective reference point is selected depending onthe individual size of the pupil determined for the respective referencepoint. Thus, the target function is evaluated preferably in a knownmanner on the vertex sphere of a model describing the system of object,spectacle lens, and eye. Here, the power of the spectacle lens iscalculated preferably by means of ray tracing and/or wavefront tracingstarting from an object point through the spectacle lens up to thevertex sphere, and is combined with the eye's refractive error projectedonto the vertex sphere in the target function. Particularly preferably,the evaluation of the wavefront for a principal ray passing through therespective reference point is performed in a surrounding of theprincipal ray which depends on the corresponding pupil size. Thereby, inparticular higher-order aberrations are corrected particularly wellaccording to the real situation of wear. Possible approaches forconsidering higher-order aberrations in particular according to furtherpreferred embodiments of the present invention will be described in moredetail further below. For example, higher-order aberrations can bemeasured individually be means of an aberrometer, for example. Inanother preferred embodiment, which will be described in detail furtherbelow, such aberrations can be obtained from statistical data inparticular in dependence on other individually determined parameters.

In a preferred embodiment, the individual position of the pupil for thesituation of wear is taken into consideration by the method comprising:determining, in particular measuring a position of a reference point ofthe eye for directions of sight that correspond to the at least tworeference points of the spectacle lens, i.e. for directions of sightthrough the respective reference point of the spectacle lens to beoptimized and produced. In a preferred embodiment, the reference pointof the eye is a point that does not shift relative to the retina whenthe brightness changes. Particularly preferably, the positions of theapex of the eye are directly or indirectly determined as the referencepoint, i.e. the apex positions can be measured directly or positions ofanother point are measured, the position thereof relative to the apexbeing known.

Preferably, optimizing comprises, for each reference point of thespectacle lens, calculating the course of a principal ray such that itpasses through the respective position of the reference point of the eyein a (individual) situation of wear of the spectacle lens, which ispreferably also specified by data of wear. The course of the principalrays, i.e. a principal ray iteration (ray tracing) as preferably used inconventional optimization methods as well, is performed preferablyindependent of the individual, brightness-dependently influenced pupilposition in this embodiment. Here, the individual pupil position isconsidered preferably by calculating a wavefront (wavefront tracing) ina surrounding of the respective principal ray such that the position ofthe surrounding relative to the principal ray is determined andconsidered according to the determined individual influence of thebrightness on the position of the pupil. In particular, in the model ofthe ray course, on which the calculation is based, an aperture stop(entrance pupil of the eye) is used, the position of which relative tothe principal ray having an individual shift depending on thebrightness. In this embodiment, the wavefront is evaluated notnecessarily in a surrounding centered around the principal ray, but inan individually shifted surrounding.

In this preferred embodiment, the positions of the reference points fordifferent directions of sight can be determined in particular togetherwith further rotation parameters of the eye without the brightnessprevailing during this measurement having to be known. To neverthelessknow the necessary reference of the pupil position to the referencepoint of the eye, the determination of an individual influence of thebrightness of the light captured by the at least one eye on the positionof the pupil of the at least one eye preferably comprises determiningthe position of the pupil relative to the reference point of the eye forthe at least one brightness target value, preferably for all specifiedbrightness target values. As explained above, this determination can beperformed either by a direct measurement with the respective brightnesstarget value or, for example, by interpolation or extrapolation on thebasis of models and/or measurements with other brightnesses.

In a further preferred embodiment, the individual position of the pupilfor the situation of wear is taken into consideration by the methodcomprising: determining, in particular measuring a position of the pupilof the eye for directions of sight that correspond to the at least tworeference points of the spectacle lens, i.e. for directions of sightthrough the respective reference point of the spectacle lens to beoptimized and produced. Since the position of the pupil preferablydepends on the brightness and this individual dependence is to be takeninto consideration, the respective position of the pupil is determinedfor a determined or determinable brightness. In a preferred embodiment,during this process, the brightness is set according to the respectivelyspecified brightness target value. In another preferred embodiment, thebrightness is measured during the measurement only as well. From anindividual influence of the brightness on the position of the pupil,which is determined particularly by a separate measurement, a positioncorrection of the respective pupil position is performed for thedifferent directions of sight based on the measured pupil position inthis case.

Preferably, optimizing in this preferred embodiment comprises, for eachreference point of the spectacle lens, calculating the course of aprincipal ray such that it passes through the respective, optionallycorrected position of the pupil of the eye in a (individual) situationof wear of the spectacle lens, which is preferably also specified bydata of wear. Thus, if the measurement of the pupil position for thedifferent directions of sight has been performed with the targetbrightness (brightness target value), preferably the directly measuredposition values will be taken into account. If, however, measurementshave been performed with a different brightness, then the pupil positionfor the purpose of principal ray iteration will be corrected preferablyaccording to the individual influence of the brightness.

The course of the principal rays, i.e. a principal ray iteration (raytracing) as preferably used in conventional optimization methods aswell, is performed depending on the individual, brightness-dependentlyinfluenced pupil position in this embodiment. On the basis of thisprincipal ray tracing, preferably a calculation of a wavefront(wavefront tracing) in a surrounding of the respective principal ray isperformed, with its position preferably not depending on the brightness.The size of this surrounding, however, preferably depends individuallyon the brightness in the way described above. In particular, in thisembodiment, an aperture stop (entrance pupil of the eye) is used in theray course model underlying the calculation, the position of theaperture stop being centered preferably with respect to the principalray.

Preferably, determining the expected individual position of the pupiland/or determining the individual influence of the brightness on theposition and/or size of the pupil comprises:

-   -   setting measurement conditions in which the brightness captured        by the at least one eye at least corresponds to a brightness        target value specified in the individual situation of wear;    -   detecting the position and/or size of the pupil of the at least        one eye (as the expected individual value) under the measurement        conditions set.

In an alternative preferred embodiment, determining the expectedindividual position of the pupil and/or determining the individualinfluence of the brightness on the position and/or size of the pupilcomprises:

-   -   specifying (defining) a relation (e.g. as an analytical        description in the form of a mathematical formula) between the        brightness captured by the at least one eye and the position        and/or size of the pupil, wherein the specified relation has at        least one individual (i.e. to be individually identified)        adaptation parameter (also referred to as a free parameter or        fit parameter);    -   identifying (in particular measuring) a position and/or size of        the pupil together with a brightness captured by the at least        one eye. That is, the (average) brightness (or the brightness to        which the pupil of the at least one eye has adjusted) prevailing        during the measurement is detected as an essential part of the        measurement conditions.    -   determining the at least one individual adaptation parameter        from the identified position and/or size of the pupil as well as        the brightness identified therewith; and    -   identifying the individual position and/or size of the pupil        expected for the predetermined brightness target value (or the        predetermined brightness target values) from the specified        relation between the brightness captured by the at least one eye        and the position and/or size of the pupil taking the determined        individual adaptation parameter into account.

In a preferred embodiment, the brightness captured by the at least oneeye, which is determined together with a position and/or size of thepupil, is measured (in particular) directly by means of a brightnesssensor.

In a in particular alternative preferred embodiment, identifying aposition and/or size of the pupil together with a brightness captured bythe at least one eye comprises:

-   -   arranging a brightness reference object close to the at least        one eye such that the brightness reference object is subjected        to the same brightness as the at least one eye;    -   collecting image data of the at least one eye together with the        brightness reference object (e.g. in one single shot, or—if        flashlight is used—preferably in direct succession, wherein the        brightness reference object is captured without flashlight); and    -   determining the brightness from the representation of the        brightness reference object in the image data.

Preferably, determining the expected individual position of the pupiland/or determining the individual influence of the brightness on theposition and/or size of the pupil comprises measuring a position of thepupil relative to a coordinate system fixed with respect to the head.Preferably, the measurement is performed by means of a video centrationsystem and using extrinsic features (e.g. spectacles frame, marks on thespectacles frame or on a clip-on element). Depending on whether thismeasurement is performed within the scope of a preferred alternativedescribed above, preferably the expected position for the specifiedbrightness target value will be measured, or a position for an arbitrarybrightness together with the brightness prevailing here will bemeasured, from which the at least one adaptation parameter for thepredetermined relation will be determined subsequently. This approach isparticularly preferred if the measurement of the position and/or size ofthe pupil is performed by means of a video centration system, which inaddition also identifies further individual parameters (for example withrespect to the selected spectacles frame) for the spectacle lensadaptation.

Preferably, determining the expected individual position of the pupiland/or determining the individual influence of the brightness on theposition and/or size of the pupil comprises measuring a position of thepupil relative to a marked feature of the at least one eye.

Preferably, determining the expected individual position of the pupiland/or determining the individual influence of the brightness on theposition and/or size of the pupil comprises specifying a direction ofsight by means of a fixation object and/or a fixation target.

In a preferred embodiment, a measurement of a position and/or size ofthe pupil is performed for a first luminance in the range fromapproximately 3 cd/m² to approximately 30 cd/m², and a measurement of aposition and/or size of the pupil is performed for a second luminance(different from the first one) in the range from approximately 0.003cd/m² to approximately 30 cd/m², preferably in the range fromapproximately 0.003 cd/m² to approximately 3 cd/m², particularlypreferably in the range from 0.003 cd/m² to approximately 0.3 cd/m²,most preferably in the range from approximately 0.003 cd/m² toapproximately 0.03 cd/m².

In a further aspect, the invention provides a measuring apparatus forcollecting individual user data that specifies at least a position of apupil of at least one eye, wherein the measuring device comprises anilluminating device adapted to determine a brightness captured by the atleast one eye. This can be done in particular in two alternative,preferred ways. The illuminating device is either adapted to control thebrightness such that a predetermined brightness is achieved, or theilluminating device comprises a sensor that measures the brightnesscauses by the (possibly non-controllable) illuminating device andpossible ambient light.

Further, the measuring apparatus comprises an image-capturing deviceadapted to collect image data of the pupil together with a positionreference point, its position relative to the eye, in particular to theretina, not depending on the brightness. The invention thus offers thepossibility of collecting user data that comprises a direct influence ofthe brightness on the position and/or size of the pupil of at least oneeye. This data can then be used to achieve a better adaptation ofspectacles or a spectacle lens.

The measuring apparatus preferably comprises a brightness sensor adaptedto measure the brightness captured by the at least one eye. Furtherpreferably, the measuring apparatus comprises a data-of-wear detectioninterface for detecting a specification for at least one brightnesstarget value and an illumination control device adapted to control thebrightness of the illuminating device such that the light captured bythe at least one eye corresponds to the detected brightness targetvalue.

In a further aspect, the measuring apparatus is not required to compriseits own illuminating unit. Instead, the ambient brightness can be usedand measured by means of a brightness sensor. In this case, themeasuring apparatus comprises:

-   -   a brightness sensor adapted to measure the brightness captured        by the at least one eye; and    -   an image-capturing device adapted to collect image data of the        pupil together with a position reference point.

Preferably, the measuring apparatus comprises a fixation target and/or afixation object and/or a fixation projection device for controlling theeye's direction of sight, i.e. in particular a light-emitting device forcontrolling or directing the direction of sight of at least one eye.Particularly preferably, the fixation target and/or the fixation objectand/or the fixation projection device is formed by the illuminatingdevice, wherein the brightness captured by the eye, which influences theposition and/or size of the pupil, is mainly provided by the fixationtarget and/or the fixation object and/or the fixation projection device.Particularly preferably, the illumination control device thus controlsthe brightness of the fixation target and/or the fixation object and/orthe fixation projection device. In the detection of the position and/orsize of the pupil or the image data of the pupil by means of themeasuring apparatus, the relevant brightness at the eye or thebrightness of the fixation target and/or the fixation object and/or thefixation projection device or the brightness of the illuminating deviceis detected and particularly stored as well.

Preferably, the measuring apparatus is designed as a video centrationsystem and/or as an auto refractometer and/or aberrometer and/orkeratograph and/or tonograph and/or pachymeter.

In a further aspect, the invention provides a computer program product,in particular in form of a storage medium or a sequence of signals,comprising computer-readable instructions, which, when loaded in astorage of a computer, preferably in the storage of a data-processingunit of an apparatus according to the present invention, in particularin one of the preferred embodiments described herein, and executed onthe computer (in particular the apparatus), cause the computer (inparticular the apparatus) to perform a method according to the presentinvention, in particular according to a preferred embodiment thereof.

After the measurement principle according to an aspect of the inventionhas been described by way of preferred embodiments, various aspects ofpreferred approaches particularly in view of applications of thesemeasurements will be discussed in the following. Finally, it will beshown exemplarily how the collected data can be preferably used in orderto adapt the centration and in particular the design of the spectaclelenses, i.e. in particular to optimize a spectacle lens individually.

In one aspect, the invention provides considering the position and/orsize of the pupil under the conditions actually present in the futureapplication. Here, conditions is understood to be also at least thebrightness in the desired application situation. In addition, otherstimuli that may influence the position and/or size of the pupil can beused as well. This relates e.g. to the accommodation of the eye atdefined distances (e.g. at infinity, in the near zone, or fogged) aswell as to special fixation or vergence positions (e.g. monocular orbinocular convergence by eye movement control via fixation targets ornear vision samples).

The measurements required for this are preferably performed with anapparatus according to the invention, which is particularly preferablydesigned as a video centration system, i.e. exhibits the functionalityof a video centration system, wherein preferably at least one of themeasurements can also be used for determining centration data or furtherindividual parameters. These can be supplemented or replaced bymeasurements with other ophthalmic optics devices.

For the required referencing of different measurements among each otherwith respect to the pupil measurements, in particular with respect tothe determinations of the position of the pupil, marked features of theeye, a fixation of the direction of sight, or referencing measurementscan be used. A detection of the position and/or size of the pupil for aspecified condition according to the invention can be performed bydirect measurement of these parameters under said condition (e.g. thespecified brightness) or by calculation from measurements at conditionsdifferent therefrom (e.g. other brightnesses).

Here, the size of the pupil is preferably defined and determinedaccording to one of the following ways:

-   -   area of the actual pupil;    -   area of the incircle or circumcircle of the actual pupil;    -   area of the circle describing the actual pupil margin best;    -   weighted area of the actual pupil. The weighting is preferably        performed as a function of the distance from a marked point for        emphasizing special regions. A thus marked point is preferably        the pupil center in particular according to one of the following        definitions or the corneal vertex.

Instead of the circle, other geometrical shapes (e.g. ellipses) can beused as well.

The position of the pupil is preferably understood to be a marked pointof the pupil in particular according to one of the followingdefinitions:

-   -   center of the actual pupil area;    -   center point of the circle describing the actual pupil margin        best;    -   center of the weighted area of the actual pupil. The weighting        is preferably performed as a function of the distance from a        marked point for emphasizing special regions. A thus marked        point is preferably the pupil center according to one of the        above definitions (e.g. for emphasizing the central region) or        the corneal vertex.

As mentioned above, in a preferred embodiment, the conditions (e.g.lighting conditions) corresponding to the future situation of wear arealready created during the measurement of an individual position and/orsize of the pupil by means of a video centration system. Thesemeasurements, in particular image data collected here, can also be usedfor determining centration data and individual data.

Additional images (image data) can be created with the video centrationsystem for further defined conditions (e.g. lighting conditions)corresponding to those of the future application, and in particular beevaluated according to the position and/or size of the pupil withoutgoing through a complete evaluation in the meaning of a videocentration.

In another preferred embodiment of collecting individual user data, apriori undefined conditions (e.g. lighting conditions) can be used aswell, which can be measured where required for the respectiveapplication. To this end, illuminating devices, such as fixation targets(i.e. direction of sight-controlling light fields) or fixation objectsfor specifying a direction of sight, which are present on the apparatusanyway, or special illuminating devices of a video centration system canbe used or provided. Of course, external illuminating devices, which mayalso be part of the store equipment of an optician, can be used as well.The same applies to fixation targets, objects, and projections. Afixation projection is understood to be the imaging system typicallyused in ophthalmic optics devices, the image of which is fixed by theviewer or to which image the viewer accommodates.

In the practical application of a video centration system with theoptician, it is often difficult to ensure the necessary brightnessconditions at the location of the video centration, which shouldcorrespond exactly to the situation of wear actually expected for thespectacle wearer. For example, video centration systems are oftenlocated in a sales room that cannot be darkened. Therefore, a furtherembodiment of a method for determining an individual position of thepupil, occurring or expected for the at least one brightness targetvalue, for at least one direction of sight of the at least one eye usesat least one further measuring apparatus with which the position of thepupil in particular with respect to a marked feature of the eye can bedetected. Such an apparatus in conformity with a preferred embodiment ofthe invention comprises at least one image-capturing device (camera)adapted to detect at least parts of the pupil margin. Further, themeasuring apparatus preferably comprises an (internal or external)illuminating device with which defined brightness conditions can becreated, i.e. the measuring apparatus is preferably adapted to controlthe brightness of the illuminating device.

Preferably, the measuring apparatus comprises a shading element forshading the eye region in order to be able to create a surrounding withlittle brightness for the eye even in a bright environment.Alternatively, the measuring apparatus can also be set up in a darkenedroom (e.g. refraction room of an optician) or a separated part of aroom.

For controlling the direction of sight, the measuring apparatuspreferably has a fixation target and/or a fixation object and/or afixation projection device, which is in particular adapted to create avirtual target. In a particularly preferred embodiment, the measuringapparatus is at the same time (i.e. integrally) designed as an autorefractometer and/or aberrometer and/or keratograph and/or tonographand/or pachymeter.

The combination with a video centration measurement is not absolutelynecessary for the centration or optimization of spectacle lenses.Instead, the changes in position and/or size of the pupil can bedetermined only with one measuring apparatus as provided by the presentinvention, and the fitting position of the lens can be determined in adifferent way (e.g. manual centration according to Viktorix) independentthereof.

Irrespective of whether the determination of an individual positionand/or size of the pupil, occurring for at least one brightness value,or the determination of an individual influence of the brightness on theposition and/or size of the pupil is performed by means of a videocentration system equipped according to the invention or by means ofanother measuring apparatus according to the invention, the measurementof the brightness at the location of the test person (spectacle wearer),in particular at the location of the eye (i.e. the brightness detectedby the eye—also referred to as the “relevant brightness”), is preferablyperformed according to one of the following possibilities.

According to a preferred embodiment, the measuring apparatus (e.g. videocentration system) comprises a wired or wireless brightness sensor thatmeasures the relevant brightness or the brightness at a point from whichit is possible to calculate back to the relevant brightness.

In another preferred embodiment, the relevant brightness is determinedby means of a brightness reference object detected in image datatogether with the at least one eye of the spectacle wearer by animage-capturing device. From the brightness of the brightness referenceobject in the image data, conclusions about the relevant brightness canbe drawn.

To avoid false measurements due to reflection or similar effects when abrightness reference object is used, an object as homogenous as possibleand scattering in a diffuse way is preferably used. The spatialexpansion is preferably selected such that the image of the objectcomprises at least the number of pixels that allows a determination ofthe brightness with the required precision. The spectral characteristicis preferably selected such that conclusions about the relevantbrightness can be drawn taking into account the spectral characteristicof the camera or the individual color channels.

In the simplest case, such a brightness reference object can be made ofa piece of white (or colored) paperboard or plastics. This piece canalso be configured to be adhesive in order to be easily attachable tothe spectacles frame or the test person in a simple and comfortable way.

Advantageously, extrinsic position reference marks disposed on thespectacles frame or a clip-on bracket can be designed such that they canbe used as brightness reference objects in conformity with thisinvention. Thereby, recordings both for determining the position of theocular center of rotation and for determining the position and/or sizeof the pupil under conditions of wear can be used in a particularlyadvantageous way, and thus both parameters can be determined with fewrecordings. In most of the video centration systems on the market,clip-on brackets are used for the geometrical calibration of camerarecordings. These can also be provided with such a brightness referenceobject.

Moreover, the selected frame can be used as a brightness referenceobject as long as its spectral characteristic is sufficiently known ordetermined in advance. The brightness reference object can also beinstalled in a stationary way in the store of the optician at a positionat which it appears in the recording and allows drawing conclusionsabout the relevant brightness. Further possible brightness referenceobjects represent the features of the person which are either known orare only subject to little variation among different test persons. Anexample of this is the sclera.

The relevant brightness is calculated from the brightness value of thepixels in the recording, which represent the brightness referenceobject, taking the spectral characteristic of the brightness referenceobject and the camera sensitivity of the relevant brightness intoaccount. In many cases, the measurement recordings are lightened byflash lighting. Due to the time scales, such additional lighting mostlydoes not have any influence on the pupil size or position. The capturedbrightness of the brightness reference object is influenced by the flashlighting though. In this case, the brightness reference object fordetermining the brightness can be captured in a prior or subsequentrecording without flashlight, i.e. with the brightness to which thepupil has adjusted in size and position.

In the determination of the individual position of the pupil fordifferent conditions (e.g. brightness, accommodation state), it isimportant to be able to determine the different positions of the pupilrelative to each other. To make this possible, different preferredembodiments for measurement methods that can be combined with each otherwill be suggested in the following. This makes particularly sense ifdifferent apparatuses are used.

In a preferred embodiment, the position of the pupil is referenced by amarked features of the eye, which is independent of the brightness inparticular with respect to a direction of sight. Preferably, as themarked feature, an intrinsic feature, such as structures on theconjunctiva or cornea as well as the limbus, or an extrinsic one, suchas a reflex of a definedly applied illuminating device on the cornea orlens (e.g. “Purkinje reflex”) is used.

If the same marked feature of the eye is detected when severalapparatuses are used (e.g. at least one measurement with a videocentration system and at least one measurement with another measuringapparatus according to the invention in one of the described preferredembodiments), the positions of the pupil determined relative theretounder different conditions can be used and calculated without anyadditional matching. Such features are preferably the above-mentionedintrinsic features and reflexes, which are based on geometricallyequivalent arrangements of the corresponding illuminating devices.

In another preferred embodiment, the position of the pupil is referencedby fixation of the direction of sight. If the position of the head doesnot change between individual measurements relative to theimage-capturing device, the positions in the image coordinate system ofthe individual recordings relative to each other can be used directly aswell. However, this requires the direction of sight to be fixed orcontrolled or measured. If the direction of sight is constant, therelative data can be used directly. In the case of possible changes ofthe directions of sight between the individual recordings, their effectcan be compensated for.

For controlling the direction of sight, preferably fixation objects orfixation targets (i.e. light fields directed in at least one plane) areused. For measuring the direction of sight, known methods of directionof sight determination (e.g. measurement of the Purkinje reflexes) canbe used.

If the position of the head changes relative to the image-capturingdevice between individual measurements (for example if severalapparatuses are used), this will preferably be compensated for byspecifying the positions of the head by at least one non-eye intrinsicor extrinsic feature.

In a further preferred embodiment, the position of the pupil isreferenced by measurements with the same brightness. If e.g. differentmarked features of the eye (e.g. different intrinsic features orreflexes with a different geometry of the illuminating units) are usedin the measurement with a video centration system and a differentindependent inventive measuring apparatus in particular according to apreferred embodiment, referencing can be performed by making at leastone recording with both systems under the same conditions—within thescope of the required accuracy. Thereby, the position of the respectivemarked features with respect to each other can be via the positions ofthe pupil, identified for this common condition, relative to theposition of the corresponding marked feature of the eye. This commoncondition does not necessarily have to be known. However, it may be—e.g.to avoid recording with an additional condition in the furthercourse—one of the conditions used later.

In a further preferred embodiment, the position of the pupil is inferredfrom the size of the pupil. In particular, first of all an individualrelation between the pupil size and the pupil position is determinedpreferably by means of a measuring apparatus according to the invention.Preferably, an analytical (e.g. linear) model with at least one freeparameter adaptable to the individual measurement is assumed for thisrelation. Preferably, this determined individual relation is thenapplied to further measurements in particular by means of othermeasuring systems (e.g. in a video centration system). In this way, forexample from image data determined with a video centration system at abrightness not known before, conclusions can be drawn on the brightnessprevailing during the measurement and the correction of the pupilposition required for a correct centration at the brightness expected inthe situation of wear by evaluation of the pupil size.

In the simplest case, the position and/or size of the pupil is/aremeasured under the conditions desired for the optimization or centrationof the lenses, i.e. conditions corresponding to the future situation ofwear. However, it is also possible to determine positions and/or sizesfor individual conditions for which no direct measurements exist.Preferably, even continuous distributions across at least regions of thespectacle lens are determined and used. In this way, preferably adistance-dependent brightness with a resulting distance-dependent pupilin progressive lenses analogous to the power distribution between nearand distance points is taken into consideration.

Preferably, parameters for a (e.g. analytically given) model areobtained from at least one measurement of the position and/or size ofthe pupil. Such a model, together with the at least one individuallydetermined parameter, preferably describes an individual influence ofthe brightness of the light captured by the at least one eye on theposition and/or size of the pupil. Preferred models are, for example,linear or logarithmic dependencies, dependencies with a free parameter,as well as interpolations or extrapolations between or via at least twosupport values. If there are more measurements than free parameters ofthe model, adaptation calculations (e.g. smallest squared deviations)can be performed to increase the precision or statistical reliability.

In a preferred embodiment, as the model for the size of the pupil(radius d in mm) in dependence on the brightness (luminance B in mL)there is used:

log(d)=a−b(log(B)+c)³

The values a=0.8558, b=0.000401, and c=8.1 can be considered as anaverage for a majority of spectacle wearers. As part of preferredembodiments of the invention, values for the parameters a, b and/or ccan be adapted by at least one measurement with at least one knownbrightness, or preferably even be determined completely by three or moremeasurements with known brightnesses.

A linear relation between the position and the size of the pupil isassumed as a preferred example of a model of the position of the pupil,the coefficients of which being determined preferably individually.Preferably, a coefficient of approximately −0.07 to approximately 0.14millimeters shift of the pupil per millimeter dilatation (change in sizeof the pupil) is specified or determined. Here, a positive value means anasal shift upon contraction. Preferably the above model can be assumedfor the pupil size.

Preferably, further stimuli (e.g. accommodation and focusing, directionof sight and vergence, etc.) that may influence the position and/or sizeof the pupil can are taken into consideration as well. The stimuli canbe provided either monocularly or binocularly as well as in arbitrarycombinations. For example, the specified individual situation of wearprimarily comprises at least one brightness target value and thusdescribes the lighting conditions in the intended individual use of thespectacles. In a preferred embodiment, a measurement in the range of thephotopic brightness (lumincances in the range from approximately 3 cd/m²to approximately 30 cd/m²) and one in the range of the mesopicbrightness (luminaces in the range from approximately 0.003 cd/mn² toapproximately 30 cd/m²) are performed. They can be supplemented bymeasurements at the boundaries between the ranges and in the scotopicrange (luminances in the range from approximately 3·10⁻⁶ cd/m² toapproximately 0.03 cd/m²).

In the consideration of accommodation and focusing, real objects (e.g.fixation objects or near vision tests) or images (e.g. the projectionsystems on the basis of a slide or CCD used in ophthalmic opticsdevices) can be used, for example. Thereby, the accommodation of the eyeat predetermined distances (e.g. at infinity, in the near zone, or“fogged” i.e. non-accommodateable) can be controlled.

Moreover, for controlling the direction of sight or for creating specialfixation or vergence positions, real objects (e.g. fixation objects,near vision tests), images, or fixation targets (i.e. light fieldspolarized in at least one plane) can be used. Here, rolling can beconsidered as well.

The thus obtained information on the position and/or size of the pupilare now in particular used for centering and/or optimizing the spectaclelenses. Some possibilities that may also be combined will be explainedin the following.

For example, the actual position is considered in the determination ofthe geometrical location of the visual points. In the simplest case, thethus obtained information on the position and/or size of the pupil isused for determining the position of individual reference or visualpoints (such as the near or distance reference points). This can also beachieved by correcting other determined parameters, such as the fittingheight and monocular pupil distance. In a preferred embodiment, the nearor distance reference point is assigned specific brightnesses and/oraccommodation states.

In particular in relation with a model for describing the influence ofthe brightness on the position and/or size of the pupil, the exactcourse (horizontal and vertical) of the principal line of sight inprogressive lenses can be completely optimized in every point accordingto the locally provided conditions (e.g. accommodation state orbrightness). Particularly preferably, in the optimization of a spectaclelens, the actual position and/or size of the pupil under the providedconditions (e.g. accommodation state or brightness) is/are taken intoconsideration.

As pointed out further above, the invention provides the possibility, inone aspect, of taking into account the pupillary play (i.e. inparticular the preferably individual dependence of the size and/orposition of the pupil on the individual situation of wear) and theassociated change in refraction (or the refraction dependent thereon) ofthe eye in the optimization and production of spectacle lenses, withoutthe higher-order aberrations (HOA) of the individual eye having to beknown or measured individually. Conventionally, the latter aredetermined with a complex wavefront measuring apparatus, which is oftennot available.

The development of individually optimized spectacle lenses, inparticular of progressive lenses, allows considering individual featuresof the spectacle wearer, such as pupillary distance, corneal vertexdistance, and individual position of wear of the spectacles. The latestspectacle lens generation is even capable of additionally considering,in the optimization of the lenses, higher-order aberrations (HOA)forming upon the refraction of light on the boundary surfaces of thespectacle lens and the eye.

In a preferred embodiment of the present invention, the optimization ofsuch spectacle lenses includes in particular the propagation andrefraction of a wavefront individually determined for each eye, saidwavefront extending across a preferably individually determined pupiland being comprised of both higher-order aberrations (HOA) andlower-order aberrations (LOA). Both the LOA and the HOA of the spectaclelens are influenced by the position of wear of the spectacle lens andare taken into account in the optimization; likewise, the HOA and theLOA of the eye and the subjectively determined refraction are taken intoaccount in the optimization.

Since the wavefront tracing is inseparably connected with the pupilsize, it is also taken into account in the optimization of the spectaclelens. Here—due to physiological phenomena, such as light reaction ofpupil near reaction—the pupil size occurring in the situation of wearmay be a function of one or more variables, such as the direction ofsight, convergence, brightness of the observed scene and/or the objectdistance. In particular in this respect is an improvement of theadaptation of a spectacle lens achieved by an individual considerationof the position and/or size of the pupil according to the invention. Todetermine not only the position and/or size of the pupil, but also thewavefront individually, an aberrometer could be used, for example. Suchdevices are usually expensive for an optician and therefore not verycommon, but they provide a very precise possibility for determination ofthe individual wavefront aberration of the eye.

As mentioned above, in one aspect, the invention provides an alternativeapproach that allows making the advantages of the latest spectacle lenstechnology widely available without an aberrometer being necessary. Asalready pointed out, the higher-order aberrations (HOA) of theindividual eye do not have to be known or measured individually. This isachieved in particular by doing without an individual wavefrontmeasurement and by replacing the individually determined wavefront andpossibly also the individually determined pupil size, which are requiredfor the optimization of the lenses, by model assumptions. By means ofthe model assumptions used in the method described here, it is alsoachieved that—compared to a conventional spectacle lens—the probabilitythat an individual person is supplied well with a spectacle lens isincreased. Thus, a method according to this aspect of the inventionimproves the care of a group of persons with spectacle lenses overall.

For a more detailed description of this aspect of the invention, someterms will be used in the following which in particular are to beunderstood as follows:

The term “data” (date of a group of eyes or of an individual eye)preferably refers to at least one type of the following data: wavefrontdata, brightness, pupil data, refraction data “other data”. Theindividual types of data will be explained in the following.

For example, the “wavefront data” describes the wavefront determined inparticular in a wavefront measurement (or on the basis of a modelassumption according to the invention). They are preferably available ascoefficients of the Zernike polynomials, so-called Zernike coefficients,at a defined pupil size and include lower-order aberrations (LOA), suchas in particular prism, sphere, astigmatism, and higher-orderaberrations (HOA), such as in particular trefoil, coma and/or sphericalaberration. The Zernike coefficients can be indicated for a standardpupil size, which may differ from the actually (individually) determinedor measured pupil size.

“Brightness” in particular refers to the luminance of the light incidenton or captured by the eye.

“Pupil data” characterizes the entrance pupil of the eye and comprisesin particular the pupil parameter of pupil size (e.g. pupil radius orpupil diameter) and preferably also one or more of the following data:pupil center (e.g. location of the center of the pupil area relative tothe apex), amplitude of the hippus, and changes in the pupil withchanging brightness of the surrounding. The pupil size and preferablyalso the pupil center must be available in the wavefront measurement;however, this and other pupil data can also be determined with othermeasuring apparatuses. In particular, the pupil size available in thepupil data may differ from the standard pupil size for which the Zernikecoefficients of the wavefront data are indicated.

The “refraction data” preferably includes sphere, cylinder, axis for thevisual distance infinity or for a different visual distance at which therefraction has been performed, as well as addition, or sphere, cylinder,axis, which are determined at a finite reading distance (e.g. 40 cm).Sphere, cylinder, and axis may also be present as so-called powervectors in an equivalent representation.

In the following, the above-mentioned “other data” of the eye isunderstood to be at least one type of the following data: brightnessincident on the eye (or captured by the eye) in the refraction (orrefraction determination), brightness incident on the eye (or capturedby the eye) in the measurement of pupil data, accommodation state of theeye, as well as age of the eye (i.e. age of the spectacle wearer).

Thus, in one aspect, the invention provides a method for optimizing andproducing a spectacle lens for at least one eye of a spectacle wearer,preferably according to one of the above-described aspects. The methodcomprises providing a distribution of data, in particular measured data,of a plurality of eyes which in particular do not include the at leastone eye of the spectacle wearer. This data of the plurality of eyes formin particular at least a part of a (statistical) set of data, which as abasis for a statistical model describes relations between differentphysical and/or physiological parameters. To this end, the data differsin the distribution of data, or the eyes of the plurality of eyes differat least partly in physical and/or physiological parameters. Thedistribution of data can be available as a sample or in the form ofanalytical models.

In a preferred embodiment, providing a distribution of data comprisesproviding a distribution of higher-order aberrations (HOA) of aplurality of eyes, which preferably depends on the parameters pupil dataand/or refraction data and/or other data.

Further, in this aspect of the invention, the method comprises providing(in particular measuring) or determining physical and/or physiologicaldata for the at least one eye of the spectacle wearer. Preferably,providing or determining physical and/or physiological data for the atleast one eye of the spectacle wearer comprises providing (in particularmeasuring) or determining refraction data of the at least one eye inparticular for at least two different reference points, preferablyaccording to at least some of the above-described details of the furtheraspects of the present invention. Here, the provided (in particularmeasured) or determined physical and/or physiological data can inparticular directly relate to or comprise such parameters on which theprovided distribution of the data of a plurality of eyes dependsdirectly, or these parameters are determined from the provided (inparticular measured) or determined physical and/or physiological data bymeans of further functional relations, as will be described in moredetail further below on the basis of preferred embodiments.

According to this aspect, the method further comprises determining mostprobably data of the at least one eye with at least one physical and/orphysiological condition. In particular, from the provided (in particularmeasured) or determined physical and/or physiological data (conditions)for the at least one eye of the spectacle wearer and/or from furtherphysical and/or physiological conditions (in particular concerning anindividual situation of wear), conclusions are drawn on the values ofthis data most possible according to the provided (statistical)distribution of the data for the at least one eye. In a preferredembodiment, conclusions are drawn on the most probable wavefront data ofthe at least one eye of the spectacle wearer with at least one pair ofpupil data and accommodation state. The thus determined most probabledata can then be used directly or indirectly in the calculation oroptimization of the spectacle lens.

Even if for this aspect of the invention, according to which use is madeof a (statistical) model (or statistical models) instead of anindividual measurement of data, the above-discussed improvements andsimplifications result especially in the determination of wavefrontdata, this aspect of the invention is not limited to the use in relationwith wavefront data. Other (statistical) relations between physicaland/or physiological data or parameters can also be used in this way fordetermining corresponding individual data. This relates particularly toa determination of an expected individual position of the pupil and/or adetermination of an individual influence of the brightness of the lightcaptured by the at least one eye on the position of the pupil of the atleast one eye and/or a determination of the individual size of the pupiloccurring or expected for the specified brightness target values. Here,the data to be determined is determined on the basis of the statisticalset of data from individually determined parameters for the eye of thespectacle wearer.

Further details in particular on preferred embodiments of the inventionwill be described by way of example in the following with reference tothe accompanying drawings

FIG. 1 is a schematic illustration of the course of a method accordingto a preferred embodiment of the present invention;

FIG. 2 is a schematic illustration of the course of a method accordingto a further preferred embodiment of the present invention;

FIG. 3 is a schematic illustration of further details of the course of amethod according to further preferred embodiment of the presentinvention, in particular according to FIG. 2.

In a preferred embodiment, the method (in particular a method foradapting an individual spectacle lens or a method for optimizing andproducing a spectacle lens) in particular comprises the method stepsillustrated in FIG. 1, which will be explained in the following.

Step A1 a: providing a distribution of the data of a group (plurality)of eyes, which depends on physical and/or physiological parameters. Thedistribution of the data of a group of eyes can be provided as a sampleor in the form of analytical models. It represents the statisticalinformation known for a group of eyes. This provided distribution ofdata is therefore also referred to as a statistics data set. Possibledata of a group of eyes is, for example, wavefront data, brightness,pupil data, refraction data, or other data of eyes, as well ascombinations thereof. Preferably, also the statistical relations betweenat least one component of this data and at least a further influencingvariable, in the following referred to as a parameter, are representedin the distribution. The parameters can be of a physical orphysiological nature. Possible parameters are pupil data, refractiondata, brightnesses, other data, or combinations thereof.

A possible analytical model of such a distribution according to apreferred embodiment is composed of a vector-valued regression functionand a multivariately normally distributed regression error. Both theregression function and the covariance matrix of the regression error isa vector or matrix-valued function of at least one of the parameters.The regression function and the covariance matrix are typically obtainedby minimizing the error squares of a sample weighted with the covariancematrix.

Each component of the regression function can be in the form of apolynomial of the parameters, which is defined section by section, andindicate the average dependence of the type of data, assigned to thiscomponent, on the parameters. In particular, such a function may, insections, be a constant function, a linear function, or a quadraticfunction of the parameters. The multivariately normally distributedregression error may, but does not have to, posses a non-diagonalcovariance matrix that can also be a function of the parameters. Such afunction (i.e. each element of the covariance matrix), like theregression function itself, can in sections be approximated as aconstant function, linear function, or quadratic function of theparameters. If in particular the regression error does not depend on theparameters, then the covariance matrix will be a constant function ofthe parameters. If there are no statistical relations between individualcomponents, then the covariance matrix will be diagonal.

Step A1 b: providing physical and/or physiological data of an individualeye. In this step, physical and/or physiological data of an individualeye for which the spectacle lens is to be calculated is provided.

Step A1 c: optionally providing most probable data WD1 of said one eye,which corresponds to one or more parameters of the distribution of stepA1 a. If required, the most probable data WD1 of the eye for which aspectacle lens is to be calculated is provided. This most probable dataof the eye corresponds to one or more parameters on which thedistribution provided in step A1 a depends.

Step A1 d: optionally providing at least one functional relation betweenthe parameters of the distribution provided in step A1 a and the data ofthe eye provided in step A1 b and/or in step A1 c. If in the followingstep A2 a statistical relation between one or more parameters of thedistribution provided in step A1 a and one or more physical and/orphysiological data provided in step A1 b or the most probable dataprovided in step A1 c is required but it is not possible to establish adirect statistical relation, then a functional relation needs to beprovided in addition. The functional relation can be obtained fromadditional sources and represents an average statistical relation.

Step A2: drawing conclusions about the most probable data W2 of said oneeye under at least one physical and/or physiological condition. Ifrequired, first of all (one or more) functional relations of step A1 dare used to convert data and/or most probable data WD1 provided for theeye in step A1 b or A1 c into the parameters on which the distributionprovided in step A1 a depends.

Next, preferably a conditional distribution of the data of a group ofeyes is calculated by evaluating the distribution of data provided instep A1 a on the data of the eye provided in step A1 b and/or the mostprobable data WD1 provided in step A1 c, which were optionallycalculated in advance by means of the functional relations provided instep A1 d.

If the distribution of the data of a group of eyes is given as a sample,then the conditional distribution will be that part of the sample theparameters of which differ sufficiently little from the data provided instep A1 b and/or the most probable data WD1 provided in step A1 c. Ifthe distribution of the data of a group of eyes is given as ananalytical approximation, then the conditional distribution will becalculated by inserting the most probable data WD1 and/or the physicaland/or physiological data of said one eye into the analyticalapproximation. If the distribution of the data of the group of eyes isin particular given as a regression model, then the conditionaldistribution of the data will result from the insertion of the data ormost probable data WD1 of said eye into the regression function and intothe covariance matrix.

Preferably, the conditional distributions of the data provided in stepA1 a result analogously with one or more physical and/or physiologicalconditions, which are required for the calculation of the spectaclelens. To this end, the previously determined conditional distribution isevaluated under the respective physical and/or physiological conditions.The most probable data WD2* of said one eye under these conditions isgiven by the maxima of this conditional distribution. The abovecalculated most probable data WD2* can be completed to form the mostprobable data WD2 of said one eye taking into consideration the dataprovided in steps A1 b and A1 c.

Step A3: directly or indirectly using the most probable data WD2 of saidone eye from step A2 in the calculation or optimization of the spectaclelens. The most probable data WD2 of said one eye determined in thepreceding step is now used in the calculation of a spectacle lens. Thiscan either be done directly, so that step A3 includes the calculation ofthe spectacle lens. But in addition to the most probable data WD2, otherinformation, such as the individually determined refraction of the eye,is taken into account as well. The most probable data WD2 can alsoindirectly be taken into account in the calculation of the spectaclelens by being used in a further method step similar to the step A1 c.

A further preferred embodiment of a method, which in particular isconsidered a preferred special case of the method described with respectto FIG. 1, will be described in the following with reference to FIG. 2.The here-described method in particular comprises the method stepsillustrated in FIG. 2.

Step B1 a: providing a distribution of the HOA of a group of eyes, whichpreferably depends on the parameters pupil data and/or refraction and/orother data. The distribution can be a sample or in the form ofanalytical models. It represents the statistical information, known fora group of eyes, on the Zernike coefficients of the higher-orderaberration (HOA) indicated for a standard pupil. If possible, thestatistical relations between at least one Zernike coefficient indicatedfor a standard pupil and at least one further influencing variable, inthe following referred to as a parameter, are to be represented in thedistribution as well. Possible parameters are pupil data, refractiondata and/or other data.

A possible analytical model of such a distribution is composed of avector-valued regression function and a multivariately normallydistributed regression error. Both the regression function and thecovariance matrix of the regression error is a vector or matrix-valuedfunction of at least one of the following parameters: pupil parameter,of the refraction data in power vector representation, the addition,age, accommodation state, LOA of the Zernike coefficients scaled to astandard pupil. The refraction data may be subjectively determinedrefraction data, or also objective refraction data determined as theZernike coefficient and pupil sizes in a suitable way. The regressionfunction and the covariance matrix are typically obtained by minimizingthe error squares of a sample weighted with the covariance matrix.

Each component of the regression function can be in the form of apolynomial of the parameters, which is defined section by section, andindicate the average dependence of the Zernike coefficient, assigned tothis component, on the parameters, wherein the Zernike coefficient isindicated for a standard pupil. In particular, such a function may, insections, be a constant function, a linear function, or a quadraticfunction of the parameters. The multivariately normally distributedregression error may, but does not have to, posses a non-diagonalcovariance matrix that can also be a function of the above-mentionedparameters. Such a function (i.e. each element of the covariancematrix), like the regression function itself, can in sections beapproximated as a constant function, linear function, or quadraticfunction of the parameters. If in particular the regression error doesnot depend on the parameters, then the covariance matrix will be aconstant function of the parameters. If there are no statisticalrelations between individual Zernike coefficients, then the covariancematrix will be diagonal.

A preferred special case of such an analytical model is the distributionof the Zernike coefficients C₃ ^(—3) to C₅ ⁵, wherein the components ofthe regression function are constant for all coefficients except for C₄⁰, and the component corresponding to the spherical aberration C₄ ⁰ is apiecewise linear function of the age. The distribution of said Zernikecoefficients is preferably a multivariate normal distribution centeredaround the averages given by the regression function, wherein saidmultivariate normal distribution may posses a different standarddeviation for each component and its covariance matrix is diagonal.

Such a model can in particular be determined from the data published bySalmon et al. (e.g. in “Normal-eye Zernike coefficients androot-mean-square wavefront errors”, J Catatact Refract Surg, Bd. 32, p.2064-2074, 2006), wherein left eyes can be transferred into right eyesby mirroring on the vertical, and the averages apply to right eyes. TheZernike coefficients of the radial order 3 to 5 are indicated for apupil diameter of 5 mm and an accommodation of 0 dpt:

C₃⁻³ = −0.02359 ± 0.044  μ m C₃⁻¹ = −0.02315 ± 0.0536  μ mC₃¹ = −0.00179 ± 0.0439  μ m C₃³ = −0.00001 ± 0.0352  μ mC₄⁻⁴ = −0.00223 ± 0.0153  μ m C₄⁻² = −0.00323 ± 0.0107  μ m$C_{4}^{0}==\left\{ {{\begin{matrix}{0.05052 \pm {0.0321\mu \; m}} & {{age} < {45\mspace{11mu} {years}}} \\{{0.05052\mspace{11mu} \mu \; m} + {{0.05\mspace{11mu} \mu \; {m \cdot \left( {{age} - {45\mspace{11mu} {years}}} \right)}\text{/}15\mspace{11mu} {years}} \pm {0.0321\mspace{11mu} \mu \; m}}} & {{45\mspace{11mu} {years}} \leq {age} \leq {60\mspace{11mu} {years}}} \\{0.10052 \pm {0.0321\mspace{11mu} \mu \; m}} & {{age} > {60\mspace{11mu} {years}}}\end{matrix}C_{4}^{2}} = {{0.00114 \pm {0.0184\mspace{11mu} \mu \; mC_{4}^{4}}} = {{0.00476 \pm {0.0168\mspace{11mu} \mu \; mC_{5}^{- 5}}} = {{{- 0.00222} \pm {0.00765\mspace{11mu} \mu \; mC_{5}^{- 3}}} = {{0.00247 \pm {0.00765\mspace{11mu} \mu \; mC_{5}^{- 1}}} = {{{- 0.00628} \pm {0.00765\mspace{11mu} \mu \; mC_{5}^{1}}} = {{{- 0.00021} \pm {0.00612\mspace{11mu} \mu \; mC_{5}^{3}}} = {{{- 0.00003} \pm {0.00459\mspace{11mu} \mu \; mC_{5}^{5}}} = {0.00001 \pm {0.00765\mspace{11mu} \mu \; m}}}}}}}}}} \right.$

wherein the notation C_(n) ^(m)=

C_(n) ^(m)

±σ_(c) _(n) _(m) is an abbreviated notation for a normal distributionaround the average (C_(n) ^(m)) with a given standard deviation σ_(C)_(n) _(m) . In the present case, the regression function is given by thevector of the averages of the Zernike coefficients (

C₃ ³

,

C₃ ¹

, . . . ,

C₅ ³

,

C₅ ⁵

), wherein all averages except for

C₄ ⁰

are constants, and

C₄ ⁰

depends on the age in the above-described way. Here, the covariancematrix is a quadratic diagonal matrix with the squared standarddeviations of the respective Zernike coefficients as diagonal elementsDiag(σ_(C) ₃ ⁻³ ², σ_(C) ₃ ⁻¹ ², . . . , σ_(C) ₅ ₃ ², σ_(C) ₅ ₅ ²).Here, all averages of the Zernike coefficients are constant functions ofthe accommodation state, but the model could be easily expanded uponavailability of corresponding Zernike coefficients depending on theaccommodation state of the eye.

Step B1 b: providing the refraction data of an eye and preferably otherdata of this eye. The refraction (sphere, cylinder, axis, at a distanceand/or near, as well as the addition) of an eye, which is detected bythe optician, ophthalmologist, optometrist, or an apparatus as astandard, is provided and converted into the power vector notation ifrequired. If possible, other data is collected as well, for exampleaccommodation state of the eye and/or age of the eye.

Step B1 c: providing the most probable pupil data of the same eye for atleast one brightness. The most probable pupil data of a specific eye,including pupil size and preferably pupil position relative to the apex,is provided. Preferably, this is done in the method illustrated in thisdocument (see in particular the corresponding details for determiningthe most probable pupil data of a specific eye according to thepreferred embodiment described further below in particular withreference to FIG. 3).

As far as possible, the most probable pupil data is based onmeasurements of the present eye. If not sufficient measurements areavailable, or if they are too imprecise, then the most probable pupildata will be determined from the distribution of the possible pupildata, which may depend on the refraction data and/or the other data ofthe eye (see auxiliary method). The most probable pupil data consists ofnumerical values (pupil size and optionally pupil position relative tothe apex) for each individual brightness, or it is available as afunction of the brightness.

The distribution of the possible pupil data represents the pupil dataconsidered possible, wherein the distribution is based on measurementsof the present eye as far as possible. The width of the distribution(standard deviation) corresponds to the standard error of themeasurements. If not enough precise or too few measurements areavailable, then the distribution of the possible pupil data of thepresent eye will be supplemented with a distribution of the pupil dataof a group of eyes, which may depend on the refraction data and/or otherdata of the eye (see in particular the corresponding details relating tothe determination of the most probable pupil data of a specific eyeaccording to the embodiment described further below in particular withrespect to FIG. 3).

The most probable pupil data is given for at least one brightness, whichwill be required later in the optimization of the spectacle lens in stepB3 or which is present during the refraction of said one eye. Inparticular, at least one brightness means a continuum of brightnesses,so that the most probable pupil data and preferably the distribution ofthe possible pupil data can be indicated with these for any arbitrarybrightness.

Step B1 d: optionally providing at least one functional relation betweenthe parameters of the distribution provided in B1 a and the dataprovided in B1 b. If in the further step (B2) a statistical relationbetween an influencing variable (e.g. the addition) and the HOA isrequired but it is not possible to establish a direct statisticalrelation between this influencing variable and the HOA, as e.g. noconnected sample of this influencing variable and the HOA exists, then afunctional relation between said influencing variable and anotherinfluencing variable (e.g. the age) needs to be provided in addition,wherein there has to be a direct statistical relation between said oneand the other influencing variable.

A possible functional relation is the one of age and accommodation widthin presbyopia, the so-called Duane curve. It can be taken from Atchisonand Smith (“The aging eye”, in Optics of the Human Eye, Edinburgh,Elsevier Science Ltd., 200, pp. 221-233), for example. If one resorts tothe common practice of selecting the addition to be ⅔ of theaccommodation width, a functional relation between addition and agebetween 45 and 60 years will result:

age=59.2 years+5.77 years/dpt·(addition+AN),

where AN is the multiplicative inverse of the near refraction distance,usually −2.5 dpt. A further functional relation is the one ofaccommodation state of the eye and the refraction data.

Step B2: drawing conclusions about the most probable wavefront data ofsaid one eye for at least one pair of pupil data and accommodationstate. If required, first of all (one or more) functional relations ofstep B1 d are used to convert data provided for the eye in step B1 binto the parameters on which the distribution provided in step B1 adepends. For example, the addition included in the refraction data needsto be converted into an age if the distribution of the pupil data instep B1 a is according to age, and the addition of said one eye includedin the refraction data in step B1 b was provided.

Next, a conditional distribution of the HOA of a group of eyes iscalculated by evaluating the distribution of HOA provided in step B1 aat the refraction data of the eye and/or the other data of said one eyeprovided in step B1 b and/or the most probable pupil data of this eyeprovided in step B1 c, which were optionally calculated in advance bymeans of the functional relations provided in step B1 d. The conditionaldistribution of the HOA is usually given for a standard pupil.

If the distribution of the HOA of a group of eyes is given as a sample,then the conditional distribution will be that part of the sample thedata of which (most probable pupil data and/or refraction data and/orother data) is sufficiently close to the data of said one eye. If thedistribution of the HOA of a group of eyes is present as an analyticalapproximation, then the conditional distribution will be calculated byinserting the most probable pupil data and/or the refraction data and/orthe other data of said eye into the analytical approximation. If thedistribution of the HOA is in particular given as a regression model,then the conditional distribution of the HOA will result from theinsertion of the data of said eye into the regression function and intothe covariance matrix.

The conditional distribution of the HOA at one or more accommodationstates of the eye, which will be required later in step B3 foroptimization, analogously result from an evaluation of the conditionaldistribution of the HOAs with corresponding accommodation states. Themost probable HOAs for the respective accommodation states are given bythe maximum of this conditional distribution.

To calculate the most probable wavefront data for the desiredaccommodation states and pupil data, lower-order aberrations (LOA) needto be determined in addition to the respective HOAs. Here, the LOAs areadapted for the most probable HOAs for the respective accommodationstate such that an objective refraction calculated based on suitablemetrics from the LOAs, the most probable HOAs and the most probablepupil data present for the refraction is identical with the subjectiverefraction provided in step B1 b.

The thus collected most probable wavefront data is finally indicated forthe pupil data required for the calculation or optimization of thespectacle lens (step B3). This pupil data was provided as most probablepupil data in step B1 c. This step particularly includes rescaling ofthe Zernike coefficients to the given pupil sizes. The most probablewavefront data is now available for at least one pair of pupil data andaccommodation state.

Step B3: optimizing a spectacle lens by using the refraction data, themost probable pupil data, and the most probable wavefront data. In thisstep, common methods are used for optimizing the spectacle lens bytaking into account the refraction data, the wavefront data, and thepupil data. Here, the wavefront data is given by the most probablewavefront data determined in step B2, and the pupil data is given by themost probable pupil data determined in step B1 c. The thus optimizedspectacle lens improves the probability of a good ophthalmic care ofsaid eye and improves the ophthalmic care of a group of persons overall.

A further preferred embodiment of the invention provides a method foroptimizing a spectacle lens by using most probable pupil data of anindividual eye. The determination of the most probable pupil data of aspecific eye according to a preferred embodiment is schematicallyillustrated in FIG. 3. The most probable pupil data determined in thismethod is preferably used further in step B1 c and is preferably finallytaken into account in the optimization of the spectacle lens in step B3.The method is preferably a special case of the method for optimizing aspectacle lens by using most probable data of an individual eye.Individual steps of this preferred method according to FIG. 3 will bedescribed in the following:

Step C1 a: providing a distribution of the pupil data of a group ofeyes, which depends on the parameters brightness, and preferablyrefraction data and/or other data. Preferably, first of all adistribution of the pupil data of a group of eyes, which depends on theparameters brightness, and is possible also on the refraction dataand/or other data, is provided. By analogy with step B1 a, thisdistribution can be a sample or in the form of an analytical model. Thedistribution represents the statistical information on the pupil dataand the refraction data and/or the other data of a group of eyes, whichis known from a group of eyes.

A possible analytical model of such a distribution is composed of avector-valued regression function and a multivariately normallydistributed regression error see paragraph on the analytical model ofthe distribution of Zernike coefficients in step B1 a). Both theregression function and the covariance matrix of the regression error isa vector or matrix-valued function of at least one of the followingparameters: the refraction in power vector representation, addition,age, accommodation state, and in particular the brightness or thelogarithm of the brightness. The regression function and the covariancematrix are typically obtained by minimizing the error squares of asample weighted with the covariance matrix. Each component of theregression function can be in the form of a polynomial of theabove-mentioned parameters, which is defined section by section, andindicates the average dependence of the pupil data, assigned to thiscomponent, on the parameters, e.g. dependence of the pupil size on thebrightness and/or dependence of the pupil position relative to the apexof the brightness. In particular, such a function may, in sections, be aconstant function, a linear function, or a quadratic function of theparameters.

The multivariately normally distributed regression error may, but doesnot have to, posses a non-diagonal covariance matrix that can also be afunction of the above-mentioned parameters. Such a function (i.e. eachelement of the covariance matrix), like the regression function itself,can in sections be approximated as a constant function, linear function,or quadratic function of the parameters. If in particular the regressionerror does not depend on the parameters, then the covariance matrix willbe a constant function of the parameters. If there are no statisticalrelations between individual components of the pupil data, then thecovariance matrix will be diagonal.

A special case of the above-described analytical model is the dependenceof a single pupil size (here considered as a pupil diameter) on age andbrightness, and has been taken from the publication of Winn et al. Theregression function d(E_(V),a) specifies the pupil diameter as afunction of the age a and the luminance in the pupil plane E_(V) in lux.With the latter, the brightness observed by the eye is modelled.

${\overset{\_}{d}\left( {E_{V},a} \right)} = {{8.95\mspace{11mu} {mm}} - {1.557\mspace{11mu} {{mm} \cdot \log_{10}}E_{V}} - {0.0509\; {\frac{mm}{year} \cdot a}} + {0.0110\; {\frac{mm}{year} \cdot a}\mspace{11mu} \log_{10}E_{V}}}$

The standard error, and thus the standard deviation of the distributionof the pupil diameters is σ_(d)=1.0 mm, irrespective of age andluminance. Altogether, the distribution of the pupil diameters is givenby

d (E _(V) ,a)˜Normal( d (E _(V) ,a),σ_(d) ²)

where Normal(x,y) is the normal distribution with expectation value xand variance y.

Another special case relates to the distribution of the change ∂d/∂log₁₀E_(V) in the pupil diameter d per logarithmic luminance log₁₀ E_(V)depending on the age. According to Winn et al., the distribution isgiven by

${\left. \frac{\partial d}{{\partial\log_{10}}E_{V}} \right.\sim{Normal}}\; \left( {{PV},\sigma_{PV}^{2}} \right)$

with

${PV} = {{{{- 0},11\mspace{11mu} \frac{mm}{{{year} \cdot \log_{10}}{lux}} \times {age}} + {1,557\mspace{11mu} \frac{mm}{\log_{10}{lux}}{and}\sigma_{PV}^{2}}} = {0,2\mspace{11mu} {\frac{mm}{\log_{10}{lux}}.}}}$

Step C1 b: providing refraction data of an eye and/or other data of thesame eye, and preferably pupil data of the same eye for at least onebrightness. Preferably, is analogous to step B1 b, which relates to theprovision of refraction data of an eye and/or other data of the eye. Ifpossible, pupil data of the eye for at least one brightness will beprovided as well, which can be attained by a measurement with a deviceor by a manual measurement, for example.

Step C1 c: optionally providing at least one functional relation betweenthe parameters of the distribution provided in step C1 a and the data ofthe eye provided in step C1 b. Preferably, like in step B1 d, functionalrelations between the parameters of the distribution provided in step C1c, which are not pupil data, and the data used in step C1 b, which arenot refraction data, are established if required. A possible functionalrelation is the relation between age and addition mentioned in step B1d.

Step C2: drawing conclusions about the most probable pupil data of saidone eye for at least one brightness. Conclusions are drawn on the mostprobable pupil data of said eye for at least one brightness. Thebrightness or the brightnesses are at least the brightness presentduring refraction, as well as further brightnesses required for theoptimization of the spectacle lens in step B3. If required, first of all(one or more) functional relations of step C1 c are used to convert dataprovided for the eye in step C1 b into the parameters on which thedistribution provided in step C1 a depends. For example, in this way,the addition included in the refraction data can be converted into anage if the distribution in step C1 a is a distribution of the pupil dataand age, and the addition of said eye included in the refraction data instep C1 b was provided.

If no pupil data or pupil data for only one brightness were provided inC1 b, then first a conditional distribution of the brightness-dependentpupil data of a group of eyes will be calculated by evaluating thedistribution provided in step C1 a for given refraction data and/orother data of an eye. The refraction data and/or other data of said oneeye may optionally have been calculated by means of the functionalrelations provided in C1 c.

If the distribution of the brightness-dependent pupil data of a group ofeyes is given as a sample, then the conditional distribution will bethat part of the sample which with respect to the refraction data and/orother data differs sufficiently little from the refraction data and/orother data of the eye. If the distribution of the brightness-dependentpupil data of a group of eyes is available as an analyticalapproximation, then the conditional distribution will be calculated byinserting the refraction data and/or other data of said eye into theanalytical approximation.

If no pupil data of said eye was provided in C1 b, then the mostprobable pupil data will be identical to the maximum of the conditionaldistribution of the pupil, evaluated for the corresponding brightnesses.If the distribution is in particular given as an analyticalapproximation, which is consists of a regression function and a normallydistributed regression error, then the most probable pupil data will begiven by the value of the regression function into which the refractiondata and/or other data of said eye and the corresponding brightnesseswere inserted.

However, if pupil of said eye was provided in C1 b, then the followingcases can be distinguished:

Case 1: providing pupil data for two or more brightnesses. In this case,the most probable pupil data is either the provided pupil data or, ifthe most probable pupil data is to be determined for other brightnesses,it is calculated by interpolation and/or extrapolation of the providedpupil data. Here, the pupil data depending on the logarithm of thebrightness are interpolated or extrapolated linearly or by means ofsplines. Since the distribution provided in step C1 a includes much lessinformation on the pupil data of said eye than the provided pupil datafor this eye, the conditional distribution of the pupil data will inthis case not be taken into account in the calculation of the mostprobable pupil data of said eye.

Case 2: providing pupil data for one single brightness. In order to drawconclusions about the pupil data for other brightnesses based on thepupil data provided, the conditional distribution of thebrightness-dependent pupil data of a group of eyes is used together withthe pupil data provided. Here, the conditional distribution is evaluatedon the pupil data provided for said eye, so that a further conditionaldistribution of the pupil data for at least one brightness results. Themost probable pupil data for at least one brightness is given by themaximum of the further conditional distribution for the correspondingbrightnesses.

Step C3: using the most probable pupil data of said one eye determinedin C2 for calculating a spectacle lens by provision in step B1 c. Thethus determined most probable pupil data of said one eye for at leastone brightness is used to provide it in step B1 c. They are therebytaken into account in the optimization of the spectacle lens in step B3.

1. A method for adapting an individual spectacle lens for at least oneeye of a spectacle wearer, comprising: specifying an individualsituation of wear, which comprises at least one brightness target valuefor light to be captured by the at least one eye; determining anindividual position, occurring or expected for the at least onebrightness target value, of the pupil for at least one direction ofsight of the at least one eye; determining a reference point of thespectacle lens, in which the spectacle lens causes a correction ofindividual refraction data required for the at least one direction ofsight; and providing and arranging the spectacle lens such that the atleast one reference point of the spectacle lens is arranged depending onthe determined individual value of the position of the pupil, in frontof the at least one eye of the spectacle wearer.
 2. A method foroptimizing and producing an individual spectacle lens for at least oneeye of a spectacle wearer, comprising: specifying an individualsituation of wear, which specifies one brightness target value for lightto be captured by the at least one eye for each of at least twodifferent reference points of the spectacle lens; determining refractiondata of the at least one eye for the at least two different referencepoints; determining an individual influence of the brightness of thelight captured by the at least one eye on the position of the pupil ofthe at least one eye; and optimizing and producing the spectacle lens,which causes a correction, destined for the reference points, of therefraction data for the positions of the pupil of the at least one eye,which result from the determined influence of the brightness on theposition of the pupil for the brightness target values specified for thereference points.
 3. The method according to claim 2, further comprisingdetermining an individual size of the pupil respectively occurring orexpected for the specified brightness target values, wherein optimizingthe spectacle lens comprises minimizing a target function which, for theat least two reference points, evaluates a correction of the refractiondata respectively determined for the respective reference point, saidcorrection being caused by the spectacle lens in a surrounding of therespective reference point, wherein the size of the surrounding of therespective reference point is selected depending on the individual sizeof the pupil determined for the respective reference point.
 4. Themethod according to claim 3, further comprising: providing adistribution of refraction data, which describe at least higher-orderaberrations, for a plurality of eyes, which differ at least partly in atleast one further physical and/or physiological parameter; determining avalue of the at least one further physical and/or physiologicalparameter for the at least one eye of the spectacle wearer; anddetermining the most probable values, according to the provideddistribution of refraction data, for the higher-order aberrations of theat least one eye of the user for the determined value of the at leastone further physical and/or physiological parameter for the at least oneeye, wherein the spectacle lens is optimized such that it corrects thehigher-order aberrations according to the determined most probablevalues at least partly.
 5. The method according to claim 1, whereindetermining the expected individual position of the pupil and/ordetermining the individual influence of the brightness on the positionand/or size of the pupil comprises: setting measurement conditions inwhich the brightness captured by the at least one eye at leastcorresponds to a brightness target value specified in the individualsituation of wear; and detecting the position or size of the pupil ofthe at least one eye under the measurement conditions set.
 6. The methodaccording to claim 1, wherein determining the expected individualposition of the pupil and/or determining the individual influence of thebrightness on the position and/or size of the pupil comprises:specifying a relation between the brightness captured by the at leastone eye and the position and/or size of the pupil, wherein the specifiedrelation has at least one individual adaptation parameter; identifying aposition and/or size of the pupil together with a brightness captured bythe at least one eye; determining the at least one individual adaptationparameter from the identified position and/or size of the pupil as wellas the brightness identified therewith; and identifying the individualposition and/or size of the pupil expected for the predeterminedbrightness target value from the specified relation between thebrightness captured by the at least one eye and the position and/or sizeof the pupil by taking the determined individual adaptation parameterinto account.
 7. The method according to claim 6, wherein the brightnesscaptured by the at least one eye, which is determined together with aposition and/or size of the pupil, is measured using a brightnesssensor.
 8. The method according to claim 6, wherein identifying aposition and/or size of the pupil together with a brightness captured bythe at least one eye comprises: arranging a brightness reference objectclose to the at least one eye such that the brightness reference objectis subjected to the same brightness as the at least one eye; collectingimage data of the at least one eye together with the brightnessreference object; and determining the brightness from the representationof the brightness reference object in the image data.
 9. The methodaccording to claim 1, wherein determining the expected individualposition of the pupil and/or determining the individual influence of thebrightness on the position and/or size of the pupil comprises measuringa position of the pupil relative to a coordinate system fixed withrespect to the head.
 10. The method according to claim 1, whereindetermining the expected individual position of the pupil and/ordetermining the individual influence of the brightness on the positionand/or size of the pupil comprises measuring a position or the pupilrelative to a marked feature of the at least one eye.
 11. The methodaccording to claim 1, wherein determining the expected individualposition of the pupil and/or determining the individual influence of thebrightness on the position and/or size of the pupil comprises specifyinga direction of sight by means of a fixation object and/or a fixationtarget.
 12. The method according to claim 1, wherein a measurement of aposition and/or size of the pupil is performed for a first luminance ina range from approximately 3 cd/m² to approximately 30 cd/m², and ameasurement of a position and/or size of the pupil is performed for asecond luminance in a range from approximately 0.003 cd/m² toapproximately 30 cd/m².
 13. A measuring apparatus for collectingindividual user data that specifies at least a position of a pupil of atleast one eye, wherein the measuring apparatus comprises: anilluminating device adapted to determine a brightness captured by the atleast one eye; and an image-capturing device adapted to collect imagedata of the pupil together with a position reference point.
 14. Themeasuring apparatus according to claim 13, further comprising abrightness sensor adapted to measure the brightness captured by the atleast one eye.
 15. A measuring apparatus for collecting individual userdata that specifies at least a position of a pupil of at least one eye,wherein the measuring apparatus comprises: a brightness sensor adaptedto measure the brightness captured by the at least one eye; and animage-capturing device adapted to collect image data of the pupiltogether with a position reference point.
 16. The measuring apparatusaccording to claim 13, further comprising: a data-of-wear detectioninterface adapted to detect a specification for at least one brightnesstarget value; and an illumination control device adapted to control thebrightness of the illuminating device such that the light captured bythe at least one eye corresponds to the detected brightness targetvalue.
 17. The measuring apparatus according to claim 13, furthercomprising at least one of a fixation target, a fixation object, and, afixation projection device adapted to control the eye's direction ofsight.
 18. The measuring apparatus according to claim 13, which isdesigned as at least one of a video centration system, an autorefractometer, an aberrometer, a keratograph, a tonograph, and apachymeter.
 19. The method according to claim 12, wherein themeasurement of a position and/or size of the pupil is performed for thesecond luminance in the range from approximately 0.003 cd/m² toapproximately 3 cd/m².
 20. The method according to claim 19, wherein themeasurement of a position and/or size of the pupil is performed for thesecond luminance in the range from 0.003 cd/m² to approximately 0.3cd/m².
 21. The method according to claim 20, wherein the measurement ofa position and/or size of the pupil is performed for the secondluminance in the range from approximately 0.003 cd/m² to approximately0.03 cd/m².